1. Field of the Invention
The present invention relates to a novel alkaline protease, method for producing the same, use thereof, and a microorganism producing the protease.
2. Description of Prior Art
In accordance with recent trend that environmental pollution has been at stake and the use of phosphoric acid salts has been restricted increasingly, it has been proposed to compound enzymes with detergents to increase their washing power. Now, various detergents containing enzymes such as proteases, amylases, cellulases, and lipases, are commercially available.
Among the enzymes, proteases are deemed as an essential component of detergents because they decompose efficiently proteinaceous dirt which occupies 10 to 40% of organic dirt sticking to cloths and is difficult to be completely removed with non-enzymatic components of detergent only.
For the protease for detergents, many enzymes derived from microorganisms have hitherto been known.
While such enzymes have enough stabilities for use as an enzyme to be compounded in solid detergents, they have rather insufficient stabilities and are inactivated in a short time in the presence of detergent components at high concentrations in liquid detergents.
Accordingly, a number of technique have been proposed in order to increase the stability of the enzymes in liquid detergents, for example, by (1) development of novel surfactants, (2) addition of stabilizers, (3) microencapsulation of enzymes (cf. Japanese Patent Application Laid-Open No. 41398/1990 (=EP 352244), U.S. Pat. No. 4,287,082, British Patent No. 2,021,142, and Japanese Patent Application Laid-Open No. 596/1987 (=EP 199405) and No. 137996/1988).
However, there is a keen desire not only for a technique for stabilizing the enzymes but also for a novel enzyme itself that has an improved stability in liquid detergents.